To bra or not to bra

I have been wondering why my healthy breast is a bit achy. At first I put it down to the fact I twisted my torso before Christmas. Then I got concerned maybe it was a cyst so I did the self examine thing but it seemed okay, however I decided to ask the onco when I see her on Friday. This morning I was talking to hubby about how I can’t currently wear a bra because when I do my mastectomy side slightly swells and feels uncomfortable by the end of the day. At that point my head went into thinking mode, unusual at the best of times. I lifted my sore boob and the pain instantly disappeared. I let it go and the pain returned. My uni boob likes to be supported and I haven’t been doing that. I am wearing my ah bra today but even that makes me uncomfortable on the mx side later in the day. Oh dear, which one should I favour?